Increasing numbers of electronic devices are becoming portable and wireless. Handheld and laptop equipment is becoming more versatile, and remotely connectable to wireless networks, the Internet and other information systems. As the equipment becomes more versatile, greater and greater masses of information are stored for subsequent retrieval. Some components and capabilities are hardwired into the units. It is also common that interface slots are provided to receive various PCMCIA cards and other equipment, as well as a variety of other data storage units that can be removed from and attached to a laptop computer or other portable device, as needed. As the versatility and adaptability of electronic devices has increased, problems associated with static charges pose an increasing threat to the reliability of the electronic equipment.
Because of increased human handling of the replaceable components, such as pc cards, it is inevitable that electrostatic discharge takes place from time to time between the person and the device. Electrostatic charges on an individual can be as high as several thousand volts, and are known to be discharged to objects and things such as electronic equipment when the person touches the equipment.
For example, a PCMCIA card frame is manufactured from conductive metal, normally stainless steel, and the receiving frame or the enclosure which will receive the PCMCIA card is also made of conductive metal that is attached to the equipment ground. Many PCMCIA cards have multiple contact points on an external surface to provide more contact with the receiving frame to discharge static charges on the PCMCIA card. However, the high charge on a PCMCIA card can cause a spark on the receiving frame or enclosure, if the static charge is high enough to break air molecules. In such situations, it is not uncommon that the high charge does not go to the receiving frame, but instead travels to any sharp point in the equipment, if the point is a least-resistance path for the charge. Such transit charges can damage delicate electronic equipment components, or can reset whole units. Simple grounding of the enclosure does not prevent the damage or nuisance frequently caused by transit charges.
What is needed in the art is an enclosure for PCMCIA cards and other data storage devices which eliminates or minimizes electrostatic discharge problems associated therewith.